C2 lnbf servicing...

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Cham

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C2 lost most of it's reception, except for the Caribbean mux on G16 and a couple of other strong TPs on other sats. Replaced it with a 741 c/ku unit I had in storage, all is back now except for my second receiver.
Took the cover off of the C2 and found a lot of white residue on the circuit board, like water had infiltrated the unit and subsequently evaporated leaving the evidence. The electronics was still working so I think there might be a chance to resurrect the board by cleaning the residue that may be ever-so-slightly conductive.

I am thinking of doing the following:
1) wash circuit with distilled water (without removing from feed horn) & let dry for a few days. Might dissolve the resedue?
2) Spray with circuit/contact cleaner
3) re-grease seal and re-assemble

Not sure if it is easily possible to remove the circuit from the feedhorn without de-soldering the probes. The back side of the board likely has residue on it too, hence using the distilled water routine... I suspect the probes are glued into the feedhorn and the board mounted after, then the connections soldered.

Has anyone done this before, or have any better ideas?

-C.
 

primestar31

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Clean it with 100% lab grade IPA. Let it evaporate back off, and it might work. I used to do it with using tight Q-tips leaving the circuit intact. Realise right up front that it might not be repairable. Don't try a drug store IPA, as it leaves too much residue.

IF you decide on water, use distilled only! Once again, shake out any larger amounts of it, and let it dry out in it's own time. I would not use a fan to dry it.
 

FaT Air

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Feb 27, 2010
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I've used hardware store denatured alcohol with great success for years. I just stay away from the "bargain" brands. I also use a flux brush with the bristles "shortened" to stiffin them, to help the alcohol loosen up the 'crusties". If using distilled water, I'd flush with alcohol to remove the water, then let the alcohol air dry(only minutes)
A short while ago used it on my C band LNBF, as I found water had infiltrated. SAVED(but replaced with a C2 because of all the good reports, now a spare. Contemplating 2nd feed on the BUD for circular.
 

Cham

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Ok,
Thanks both of you for your pointers, glad someone has had luck doing this sort of operation already. I have some IPA but only 99%, use it for cleaning electronic parts etc but it is old so a trip to the electronics supply store will be in order before attempting this.
Think I'll use the distilled water first (maybe two soakings), then the IPL. Contact cleaner (some types) leaves an oily film I was thinking might repel moisture in the future... but best to keep it out in the first place.
 

Anole

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Sep 22, 2005
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The board is bare with no protective coating?
When I worked in aerospace, on military projects, a board exposed to harsh weather would be conformal coated.
Unfortunately, they'd also cost 50 times as much. ;)

Considering the frequencies involved, I can't think of any protectant we could get, that wouldn't do more harm than good.
Probably best would be to keep it sealed at top, and vented below.
That still would leave you subject to high humidity and condensation.
Last thought might be to seal it with dry nitrogen.

Not really any workable ideas, sadly.


iphone 4
 

Corrado

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Apr 2, 2007
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I have been using several of the C2s here on the 6' dishes with no issues. The only observation I can see when they are uncovered, is slight rust near the cable ports. Mine are kept covered.

I bought a bunch for the deal that was on at the time and for that money, I wouldn't waste my time attempting to repair any of them. I can find so little spare time as it is.

There is nothing I hate worse than sitting down to watch something (especially recording ) and having the picture or reception broken up.
 

wallyhts

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C2 lost most of it's reception, except for the Caribbean mux on G16 and a couple of other strong TPs on other sats. Replaced it with a 741 c/ku unit I had in storage, all is back now except for my second receiver.
Took the cover off of the C2 and found a lot of white residue on the circuit board, like water had infiltrated the unit and subsequently evaporated leaving the evidence. The electronics was still working so I think there might be a chance to resurrect the board by cleaning the residue that may be ever-so-slightly conductive.

I am thinking of doing the following:
1) wash circuit with distilled water (without removing from feed horn) & let dry for a few days. Might dissolve the resedue?
2) Spray with circuit/contact cleaner
3) re-grease seal and re-assemble

Not sure if it is easily possible to remove the circuit from the feedhorn without de-soldering the probes. The back side of the board likely has residue on it too, hence using the distilled water routine... I suspect the probes are glued into the feedhorn and the board mounted after, then the connections soldered.

Has anyone done this before, or have any better ideas?

-C.

Can we see a Picture of inside? :)
 

Cham

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Yes sure can (pictures). Not sure how well they show the resedue. Not used to taking close-ups...

IMG_0327 (Medium).JPG IMG_0326 (Medium).JPG

Think I need something to hold the camera steady & better lighting.
 

wallyhts

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Cham said:
Yes sure can (pictures). Not sure how well they show the resedue. Not used to taking close-ups...

<img src="http://www.satelliteguys.us/attachment.php?attachmentid=80386"/><img src="http://www.satelliteguys.us/attachment.php?attachmentid=80387"/>

Think I need something to hold the camera steady & better lighting.

What a nightmare.

Sent from my iPhone using SatelliteGuys
 

Cham

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Well I seem to have the C2 working again. Washed with distilled water and old soft bristled toothbrush, then rinsed, again using distilled water. Then right after I soaked it in IPA for a while and let it dry for a day or so. It's been operating now for 5 days with no issues so far, seems to be working like new.
Added some lubriplate to the seal when re-assembling to help seal it. Used some dielectric grease inside the connectors when re-attaching the feedlines.
Keeping my fingers crossed!
-C.
 

polgyver

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Well I seem to have the C2 working again. Washed with distilled water and old soft bristled toothbrush, then rinsed, again using distilled water. Then right after I soaked it in IPA for a while and let it dry for a day or so. It's been operating now for 5 days with no issues so far, seems to be working like new.
Added some lubriplate to the seal when re-assembling to help seal it. Used some dielectric grease inside the connectors when re-attaching the feedlines.
Keeping my fingers crossed!
-C.
Did you take a picture of the LNB board after washing? Congratulations on making it work! Cheers, polgyver
 

wallyhts

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polgyver said:
Did you take a picture of the LNB board after washing? Congratulations on making it work! Cheers, polgyver

I agree nice. (would have liked but on iPad)
 

Cham

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Sorry fellows I didn't think to take a picture. The board didn't really look much different other than some residue is gone now. It is back in service on an 8' dish since mid last week for reception of the BYU HD channel conference. Signal from that TP on G17 was abysmal and the picture was breaking up quite a bit so had to set up a Ku dish for the NA Backup channel on G28. The signal issue was not likely an LNBF issue even on my 10' dish the signal was marginal.
 

wallyhts

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Sorry fellows I didn't think to take a picture. The board didn't really look much different other than some residue is gone now. It is back in service on an 8' dish since mid last week for reception of the BYU HD channel conference. Signal from that TP on G17 was abysmal and the picture was breaking up quite a bit so had to set up a Ku dish for the NA Backup channel on G28. The signal issue was not likely an LNBF issue even on my 10' dish the signal was marginal.

Yup BYU on g17 is a nightmare. However mike kohl told me that he had a customer switch to a norsat lnb (DRO) and had no problem after that.
 

primestar31

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BYU on 91w (G17) comes in crystal-clear on the MicroHD and with my 10 foot "Perfect Ten" dish with ortho-feed and Norsat 8115's. I've been recording some old Walt Disney movies from it over the last two weeks or so. I love the old Walt Disney movies!
 

wallyhts

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primestar31 said:
BYU on 91w (G17) comes in crystal-clear on the MicroHD and with my 10 foot "Perfect Ten" dish with ortho-feed and Norsat 8115's. I've been recording some old Walt Disney movies from it over the last two weeks or so. I love the old Walt Disney movies!

Nice. I wonder what media format byu is using?
 

Cham

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I have a few DRO LNBs kicking around but only feedhorns I have are polarotor that newer receivers don't play with. Maybe have to find an orthomode and try it out...
 
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